Abstract

We report on the structural and optical properties of 6,13-pentacenequinone thin filmsdeposited on -Si substrates by thermal evaporation at room temperature. X-ray diffraction data indicate excellent crystallinity but the films have two crystalline phases mixed. Photoluminescence(PL)spectra exhibited double peaks at 1.97 and 2.09 eV while the corresponding (double) peaks, associated with the highest occupied molecular orbital–lowest unoccupied molecular orbital transition, were also observed from direct absorption spectra at 2.94 and 3.11 eV. The yellow PL band was quite intense under UV illumination; the intensity was comparable to that from Tris-(8-hydroxyquinoline) aluminumthin films. A large Stokes shift of found in our 6,13-pentacenequinone thin films suggests potential applications to UV-detectors and UV-detecting cards.

Received 06 July 2004Accepted 14 October 2004Published online 08 December 2004

Acknowledgments:

The authors are very appreciative of the financial support from KISTEP (Program No. M1-0214-00-0228), and they also acknowledge the support from Brain Korea 21 Program. J.H.K acknowledges financial support from electron Spin Science Center at Postech, funded by KOSEF.